Diseases of the Periradicular Tissue DEPARTMENT OF ORAL

Diseases of the Periradicular Tissue DEPARTMENT OF ORAL MEDICINE & RADIOLOGY Dentistry Explorer

The area present beyond the tooth apex v Cementum: mineralized, avascular connective tissue Growth factors: cementoblast proliferation, migration and differentiation during wound healing. Ø Insulin like growth factors Ø Fibroblast growth factors Ø Epidermal growth factors Ø Bone morphogenetic proteins Ø Transforming growth factors Ø Platelet derived growth factors Dentistry Explorer

v Periodontal ligament: specialized connective tissue Cells: Ø Ø Ø Ø Osteoblast Osteoclast Fibroblast Epithelial cell rests of Malassez Macrophages Cementoblasts Undifferentiated mesenchymal cells (stem cells) Multipotent stem cells of Pdl are capable of differentiating into cementoblast- like cells, periodontal ligament cells, osteoblasts. Dentistry Explorer

v Alveolar bone: Outer cortical plate, central spongy or cancellous bone, and bone lining sockets q Bone matrix contains: Ø Insulin like growth factors Ø Fibroblast growth factors Ø Epidermal growth factors Ø Bone morphogenetic proteins Ø Transforming growth factors Ø Platelet derived growth factors Osteoblast proliferation, migration, differentiation during wound healing. Dentistry Explorer

Ø Injury to any calcified structures of the teeth by any noxious stimuli will cause changes in both pulp and periradicular tissue. Ø Apical periodontitis can be protective or destructive : Dynamic interaction between microbial insult and host defense. Ø Bacterial biofilm in the root canal system with necrotic pulp is protected form host’s defenses and antibiotic therapy due to the lack of blood circulation. Dentistry Explorer

Etiological factors: v. Pulp inflammation & pulp necrosis – Bacteria, bacterial products and inflammatory mediators v. Trauma v. Periodontal disease v. Endodontic procedures – Pulp extirpation – Root canal instrumentation – Root canal irrigants/ obturating materials Dentistry Explorer

v. Endogenous factors: Host’s metabolic products urate, cholesterol crystals, cytokines or other inflammatory mediators that activate osteoclasts. Dentistry Explorer

HOW DOES A PULP DIE? IRRITATION TO CLINICAL CROWN LOCALIZED PULPAL INFLAMMATION INITIAL INSULT LOCALIZED EFFECT INCREASED LOCAL TISSUE PRESSURE VENOUS COLLAPSE STASIS ISCHEMIA LOCAL NECROSIS RELEASE OF INFLAMMATORY MEDIATORS MECHANISM OF SPREAD CIRCUMFERENTIAL VASCULAR DISTURBANCE INCREASED TISSUE PRESSURE LOCAL NECROSIS OF ADDITIONAL TISSUE TOTAL PULPITIS Dentistry Explorer

The pathway of the pulp and periapical pathosis set out from caries Dentistry Explorer

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Microbiology of Endodontic Infections • Apical periodontitis is essentially an inflammatory disease of microbial etiology primarily caused by infection of the root canal system. • Biofilm-induced oral diseases Dentistry Explorer

q Bacterial structural components, – – – – lipopolysaccharide (LPS), peptidoglycan, lipoteichoic acid, fimbriae, flagella, outer membrane proteins and vesicles, lipoproteins, DNA, and exopolysaccharides Stimulate the host immune reactions Capable of defending the host against infection severe tissue destruction Dentistry Explorer

LTA Cytoplasmic membrane Cell wall Flagellum PG CM Gram-positive LPS Chromosome Ribosomes Exopolysaccharide (capsule) Fimbriae Plasmids OMP OM LPtn PG CM Gram-negative Bacterial cell and its structural components that can act as virulence factors. Detailed scheme of the bacterial cell walls from gram-positive and gram-negative bacteria. CM, Cytoplasmic membrane; LPS, lipopolysaccharide (endotoxin); LPtns, lipoproteins; LTA, lipoteichoic acid; OM, outer membrane; OMP, outer membrane protein; PG, peptidoglycan. Dentistry Explorer

Types of Endodontic Infections According to anatomic location v. Intraradicular infection is caused microorganisms colonizing the root canal system by ØPrimary infection, microorganisms that initially invade and colonize necrotic pulp tissue ØSecondary infection, not present in the primary infection but introduced in the root canal at some time after professional intervention Dentistry Explorer

Ø Persistent infection, members of a primary or secondary previously noninfected tooth v. Extraradicular infection Is characterized by microbial invasion of the inflamed periradicular tissues and is a sequel to the intraradicular infection. Dentistry Explorer

The Infectious Process Sites of established infection – Main pulp canal space and walls – Accessory canals and apical delta – Dentinal tubules – Cementum surface – Extraradicular colonizations Dentistry Explorer

Diversity of the Endodontic Microbiota Ø There an estimated 10 billion bacterial cells in the oral cavity Ø More than 400 different microbial species/phylotypes have been found in infected root canals Ø Primary infections are characterized by a mixed community conspicuously dominated by anaerobic bacteria. Ø The number of bacterial cells may vary from 103 – 108 per root Canal. Dentistry Explorer

Ø Molecular studies have disclosed a mean of 10 to 20 species/phylotypes per infected canal. Ø Canals of teeth with sinus tracts exhibit a mean number of 17 species. Ø The size of the apical periodontitis lesion has been shown to be proportional to the number of bacterial species and cells in the root canal. Dentistry Explorer

gram-negative Fusobacterium, Dialister, Porphyro. Firmicutes monas, Prevotella, Tannerella, Treponema, Campylobacter, and Veillonella gram-positive Parvimonas, Filifactor, Pseudoramibacter, Olsenella, Actinomyces, Peptostreptococcus, Streptococcus, Propionibacterium, and Eubacterium Dentistry Explorer

Prevalence of bacteria detected in primary infections of teeth with chronic apical periodontitis ØDialister invisus ØBacteroidetes clone X 083 ØPseudoramibacter alactolyticus ØPorphyromonas endodontalis ØTreponema denticola ØDialister pneumosintes ØFilifactor alocis ØTannerella forsythia ØTreponema parvum ØPrevotella baroniae Dentistry Explorer

Primary infections of teeth with acute apical periodontitis Ø Treponema denticola Ø Dialister invisus Ø Pseudoramibacter alactolyticus Ø Bacteroidetes clone X 083 Ø Tannerella forsythia Ø Porphyromonas endodontalis Ø Porphyromonas gingivalis Ø Propionibacterium propionicum Ø Treponema maltophilum Ø Treponema socranskii Dentistry Explorer

Prevalence of bacteria detected in primary infections of teeth with acute apical abscesses Ø Treponema denticola Ø Porphyromonas endodontalis Ø Dialister pneumosintes Ø Tannerella forsythia Ø Porphyromonas gingivalis Ø Dialister invisus Ø Filifactor alocis Ø Fusobacterium nucleatum Ø Streptococcus species Ø Propionibacterium propionicum Dentistry Explorer

The main sources of nutrients for bacteria colonizing the root canal system include: q The necrotic pulp tissue q Proteins and glycoproteins from tissue fluids and exudate that seep into the root canal system via apical and lateral foramens; q Components of saliva that may coronally penetrate into the root canal; and q Products of the metabolism of other bacteria. Dentistry Explorer

Other Microorganisms in Endodontic Infections v. Fungi : q Candida species v. Archaea v. Viruses : patients infected with the human immunodeficiency virus q Human cytomegalovirus q Epstein-Barr virus Dentistry Explorer

Ecological conditions in different areas of the root canal. A gradient of oxygen tension and nutrients (type and availability) is formed. Consequently, the microbiota residing in different parts can also differ in diversity, density, and accessibility to treatment procedures. Dentistry Explorer

Tissue changes following Inflammation Either degenerative or proliferative v Degenerative Changes: q Fibrous, resorptive, or calcific. q If degeneration continues, necrosis will result, especially if thrombosis of blood vessels occur. q Polymorphonuclear cells injury release proteolytic enzymes, resulting liquefaction of the dead tissue. Dentistry Explorer

q For Suppuration: Ø Necrosis of the tissue cells Ø Sufficient number of polymorphonuclear leukocytes Ø Digestion of the dead material by proteolytic enzymes. q Abscess is formed because the enzymes digest not only the leukocytes, but also the adjacent dead tissue. Dentistry Explorer

v Proliferative Changes q Mild irritants. q In the center of inflammatory area. , the irritants may be strong enough to produce degeneration, whereas at periphery irritant may be mild enough q Principal cells of repair are the fibroblasts, which lay down cellular fibrous tissue. Dentistry Explorer

Reaction of periradicular tissues to noxious products: Fish • Experimental foci of infection in the jaws of guinea pigs • Four zones of infection I: Zone of Infection: (Zone of Necrosis) ü Polymorphonuclear leukocytes. ü Center of the lesion ü Microorganisms present Dentistry Explorer

II: Zone of Contamination: ü Round cell infiltration, Macrophages ü Cellular destruction from toxins discharged from central zone ü Autolysis of bone cells, empty lacunae. ü Lymphocytes prevalent Dentistry Explorer

III: Zone of Irritation: (Granulomatous zone) Macrophages, lymphocytes, plasma cells and osteoclasts Toxins become diluted The collagen framework digested by phagocytic cells Osteoclasts act upon bone tissue Resulting activity open up gap in the bone around the lesion ü Occasionally Russel bodies, foam cells, cholesterol crystals and epithelial clusters are seen ü ü ü Dentistry Explorer

IV: Zone of Stimulation: ( Zone of encapsulation, zone of productive fibrosis) ü ü Fibroblasts and osteoblasts Toxins mild Collagen fibers laid down by fibroblasts Osteoblast: bone synthesis in irregular fashion q Non-surgical root canal therapy of teeth with periapical pathosis: Elimination of microbes (Zone I) from canal & obtain an impermeable seal. Dentistry Explorer

10 Questions and Answers About Dental Radiographic Interpretation 1. What is the earliest radiographic sign of periapical disease of pulpal origin? The earliest radiographic sign is widening of the periodontal ligament space around the apex of the tooth. 2. What is the second most common radiographic sign of periapical disease of pulpal origin? The second most common radiographic sign is loss of the lamina aura around the apex of the tooth. Dentistry Explorer

Classification: • Acute periradicular lesions; – Acute apical periodontitis • Vital • Non vital – Acute alveolar abscess – Acute exacerbation of chronic lesion (Phoenix abscess) Dentistry Explorer

• Chronic periradicular lseions: – Chronic alveolar abscess – Granuloma – Cysts • Condensing osteitis • External root resorption • Disease of periradicular tissues of nonendodontic origin Dentistry Explorer

Ingle’s Classification: • Apical Periodontitis – Acute apical periodontitis (symptomatic) – Chronic apical periodontitis (asymptomatic) • Apical abscess – Acute apical abscess – Chronic apical abscess – Phoenix abscess Dentistry Explorer

• Non- endodontic periradicular lesion – Odontogenic cysts • • • Primordial cyst Dentigerous cyst Lateral periodontal cyst Odontogenic keratocyst Residual apical cyst – Fibro- osseous lesions • Periradicular cemental dysplasia • Osteoblastoma & Cementoblastoma • Cementifying and ossifying fibroma Dentistry Explorer

• Odontogenic tumors – Ameloblastoma • Non- odontogenic tumors – Central giant cell granuloma – Nasopalatine duct cyst Dentistry Explorer

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Symptoms of periapical pathosis generally • Anamnesis: – acute: pain, swelling – chronic: mild or no symptoms • Clinical examination: – vitality test: usually negative • Radiological symptoms Dentistry Explorer

Acute Alveolar Abscess v Acute abscess/ acute apical abscess/ acute dentoalveolar abscess/ acute periapical abscess/ acute radicular abscess. v Definition: A localized collection of pus in the alveolar bone at the root apex of a tooth following death of the pulp with extension of the infection through the apical foramen into the periradicular tissues. Dentistry Explorer

v Etiology: q Result of trauma, chemical or mechanical irritation q Bacterial invasion of the dead pulp tissue. v Symptoms: Local Ø Severe throbbing pain with swelling of overlying soft tissue. Ø Swelling progresses & tooth becomes mobile. Ø Formation of sinus tract in the labial or buccal mucosa. General Ø Pale, irritable, weak, headache, malaise Ø Fever with chills Ø Foul breath. Dentistry Explorer

v Diagnosis: 1. Clinical: • • Subjective symptoms Tender on percussion Tender on palpation of apical mucosa Mobile & extruded tooth 2. Radiographic: • A cavity, a defective restoration, thickened periodontal ligament space, evidence of bone loss in the apical root region. Dentistry Explorer

Differential Diagnosis: Ø Periodontal abscess Ø Irreversible pulpitis Treatment: Ø Establishment of drainage Ø Antimicrobial therapy Ø Root canal treatment Dentistry Explorer

Acute apical periodontitis Etiology: q Vital tooth: occlusal trauma Ø Recently inserted restoration extending beyond the occlusal plane Ø Wedging of a foreign object between teeth Ø Direct insult q Non vital tooth: Ø Sequela of the pulp disease Ø Iatrogenic Dentistry Explorer

Clinical features: – symptoms of pulpitis or necrosis – Tooth may be extruded Diagnosis: o Tender to percussion X-ray: – thickening of periodontal ligament space Differential diagnosis Acute alveolar abscess Treatment: – Root canal treatment, (adjustment of occlusion) Dentistry Explorer

3. Describe the radiographic differences that allow one to distinguish among periapical abscess, granuloma, radicular (periapical) cyst, and an apical surgical scar. Ø Ø Ø One cannot distinguish among periapical abscess, granuloma, or radicular (periapical) cyst on radiographic grounds alone. All of these lesions are radiolucent with well-defined borders. Whereas an abscess may be expected to be less well corticated than a radicular cyst, this feature is not marked or constant enough to be of real utility. An apical surgical scar may be radiographically distinguishable from the other three lesions if there is radiographic evidence of surgery, such as a retrograde amalgam. Of course, a history should elicit the fact of surgery. Dentistry Explorer

Acute exacerbation of a chronic lesion (Phoenix abscess) v An acute inflammatory reaction superimposed on an existing chronic lesion such as a cyst or granuloma. v Etiology: Ø Periradicular disease. Ø Bacteria released from root canal during instrunentation may trigger acute response. Dentistry Explorer

v Symptoms: Ø Tender to palpation Ø Tooth may be elevated in its socket Ø Mucosa over the radicular area appears red and swollen. v Diagnosis: Ø Associated with the initiation of RCT Ø History of trauma v Differential diagnosis: Ø Acute irreversible pulpitis v Treatment: Ø RCT Dentistry Explorer

4. How does the radiographic appearance of pulpal pathology that has extended to involve the bone differ in primary posterior teeth from the picture commonly seen in permanent posterior teeth? In permanent teeth, widening of the periodontal ligament space is seen around the apex of the tooth. Ø In primary teeth, by contrast, the infection presents as widening of the periodontal ligament space or an area of radiolucency in the furcation area. Ø 5. Does any radiographic sign permit the diagnosis of a nonvital tooth? The presence of a root canal filling in a tooth provides virtually conclusive proof of its nonvitality, as does the presence of a retrograde filling, usually amalgam. Dentistry Explorer

Chronic apical periodontitis • Symptoms: – asymptomatic or slight discomfort • Clinical examintaion: – little or no pain on percussion • X-ray: – interruption of lamina dura or apical radiolucency • Treatment: – root canal treatment Condensing osteitis: radiopaque Dentistry Explorer

Chronic Alveolar Abscess (Chronic Suppurative Apical Periodontitis) v A long standing low grade infection of the periradicular alveolar bone. v Clinical features: Ø Generally asymptomatic (drain) , swelling Ø Sinus tract Ø When open cavity present drainage occurs through root canal. Dentistry Explorer

v Clinical examination: – fistula, swelling v X-ray: – radiolucent lesion (localisation with guttapercha) v Treatment: – root canal treatment Dentistry Explorer

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Granuloma: v A growth of granulomatous tissue continuous with the periodontal ligament resulting from death of the pulp and the diffusion of bacterial toxins from the root canal into the surrounding periradicular tissues through the apical and lateral foramina. v Etiology: Ø Death of pulp. Ø Irritation of periapical tissue that stimulates a productive cellular reaction. Ø In some cases a granuloma is preceded by a chronic alveolar abscess Dentistry Explorer

Symptoms: Ø Usually asymptomatic Ø A granuloma may not produce any subjective reaction, except in rare cases when it breaks down and undergoes suppuration. Diagnosis Routine radiographic examination palpation Pulp Vitality tests Differential Diagnosis: Cementoma Periapical osteofibrosis Treatment: RCT Dentistry Explorer

Radicular Cyst: v A slowly growing epithelial sac at the apex of a tooth that lines a pathological cavity in the alveolar bone. v. Etiology: Ø Pulp necrosis followed by stimulation of the epithelial cells of Malassez. Dentistry Explorer

v Clinical features: Ø Swelling, tooth mobility Ø Maxilla > Mandible v Radiograph: Ø Break in continuity of lamina dura. Ø Oval shaped radiolucency more than 2 cm. v D/d: Ø Granuloma Ø Normal bony structure such as incisive foramen Ø Globulomaxillary cyst Ø Traumatic bone cyst v Treatment: Ø Root canal therapy Ø Marsupilization Dentistry Explorer

6. At times it may be difficult to distinguish between hypercementosis and condensing or sclerosing osteitis around the apex of a tooth. What radiographic feature permits a definitive diagnosis. Ø If hypercementosis is present, the periodontal ligament space is visible around the added cementum; that is, the cementum is contained within and is surrounded by the periodontal ligament space. Ø Condensing osteitis, by contrast, is situated outside the periodontal ligament space. 7. What is the radiographic sign of an ankylosed tooth? The radiographic sign of an ankylosed tooth is loss of the periodontal ligament space and lamina aura. Dentistry Explorer

Condensing Osteitis: The response to a low grade chronic inflammation of the periradicular area as a result of a mild irritation through the root canal. Ø Asymptomatic, revels during routine radiolographic examination. Radiography: Ø Localized area of radiopacity surrounding the affected root. Ø An area of dense bone with reduced trabecular pattern. Treatment: RCT Dentistry Explorer

External root resorption: A lytic process occuring in the cementum or cementum & dentin of the roots of teeth. Etiology: Ø Idiopathic Ø Periradicular inflammation due to trauma, excessive forces, granuloma, cyst, central jaw tumors, replantation of teeth, bleaching of teeth, impaction of teeth. Dentistry Explorer

Symptoms: Ø Asymptomatic Ø When root is completely resorbed: tooth mobility Ø If the external root resorption extends into the crown it will give the appearance of pink tooth seen in internal resorption. Treatment: Ø treatment varies with etiology Ø RCT Ø Reduce the excessive forces from orthodontic appliances. Ø MTA Dentistry Explorer

8. What is the earliest radiographic sign of periodontal disease? The earliest radiographic sign of periodontal disease is loss of density of the crestal cortex, which is best seen in the posterior regions. Ø In the anterior part of the mouth, the alveolar crests loose their pointed appearance and become blunted. Ø In the posterior areas, the alveolar crests usually meet the lamina aura at right angles. In the presence of periodontal disease, these angles become rounded. Ø Dentistry Explorer

Harald Eriksen 2008 in: Ørstavik & Pitt Ford, Essential Endodontology Maintaining a high number of retained teeth into old age is a goal common to all of dentistry; Endodontology deals with bringing down the prevalence of apical periodontitis Dentistry Explorer

Natural Course of the Disease: • Unpredictable if untreated • It does not heal • Potentially very painful • Serious complications/sequelae are rare Filling therapy Endodontics Extraction Pulpitis ->Necrosis->Apical Perio->Acute phases->Local spread->Systemic spread Dentistry Explorer

9. What is the earliest radiographic sign of furcation involvement due to periodontal disease? Ø In periodontal disease, one may see the loss of a cortical plate, either the buccal or lingual plate, on an intraoral film. Ø The plate may be lost so that the crest now occupies a position apical to the furcation. This appearance, however, does not permit a diagnosis of furcation involvement. Ø Widening of the periodontal ligament space in the furcation area is the earliest radiographic sign of furcation involvement. 10. What is the radiographic differential diagnosis of a radiolucency on the root of a periodontally healthy tooth? Internal resorption, external resorption, and superimposition are the most common causes. Dentistry Explorer

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